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15 for '15: The best 2015 NBA draft prospects already in college

Willie Cauley-Stein will have to fight off talented freshmen to earn a starting spot at Kentucky, but if he does, the 7-footer will be a coveted prospect. (Stacy Revere/Getty)

It's never too early to talk about the 2015 NBA draft, even if it's weeks before the 2014 draft takes place. Next year's likely top pick, incoming Duke freshman Jahlil Okafor, hasn't arrived on campus yet, but there will be plenty of returning talent that has the potential to push the touted-but-unproven incoming freshman class for slots in next year's draft. Here's a look, in alphabetical order, at 15 returning college players who could rate among the top NBA prospects next June:

Were it not for the torn ligament in his right foot that ended his 2013-14 season in February, Ashley may have entered this year's draft. But he'll be back in Tucson for his junior season after averaging 11.5 points and 5.8 rebounds as a sophomore. If he improves those numbers, he'll be a valued commodity at 6-foot-8, 230 pounds and with an ability to guard multiple positions.

The 6-6 guard averaged 8.3 points on 42.5 percent shooting as a freshman and can play multiple positions. Both Draft Express and NBA DraftNet place Bird as a first-round pick in their very early projections for the 2015 draft. He'll get a chance under new coach Cuonzo Martin to assume a bigger role next season with two of Cal's top four scorers having departed, and if he succeeds, he could vault up the charts.

Willie Cauley-Stein, Kentucky

The modest 8.3 points and 6.2 rebounds per game Cauley-Stein averaged as a sophomore don't matter. Nor does the fact that he came off the bench for most of last season. What does matter are his 7-foot, 250-pound frame and 166 career blocked shots. Even with a foot injury suffered during the NCAA tournament, Cauley-Stein likely would have been a first-round pick this year for his size and ability to protect the rim. The overcrowded Kentucky frontcourt for next season – Dakari Johnson and Marcus Lee return while touted recruits Karl Towns and Trey Lyles arrive – shouldn't alter perceptions of what Cauley-Stein offers.

Harrell's decision to return for his junior season was among this offseason's most surprising draft calls, given that he broke out with 14.0 points and 8.4 rebounds per game on 60.9 percent shooting in 2013-14. He's 6-8 and 235 pounds already. While his 46.4 percent efficiency from the free throw line is atrocious, Harrell's physicality and aggressiveness on the glass – his 120 offensive rebounds ranked 13th nationally – will get him scooped up early next June.

The twins were borderline first-round draft picks by most estimations before deciding to return to Lexington for their sophomore seasons. Even with the arrival of touted recruits Tyler Ulis and Devin Booker, the Harrisons should hold down the bulk of the backcourt minutes. At 6-6 apiece, they have the size to intrigue NBA teams. If Andrew Harrison progresses into another Deron Williams-type point guard and Aaron Harrison scores consistently and retains the clutch touch he demonstrated with multiple NCAA tournament buzzer-beaters, they should be more comfortably in the first-round range next summer.

Hollis-Jefferson announced he was returning to Arizona after averaging a mere 9.1 points and 5.7 rebounds per game as a freshman. The need to make a public proclamation either suggests everyone is getting way ahead of themselves, or there's just enough evidence that the NBA sees untapped potential in the 6-foot-7 swingman. Hollis-Jefferson should have a more featured scoring role with Nick Johnson and Aaron Gordon departing, and that could pave his way to the lottery.

Johnson will need to fill out both his frame and his game -- he's listed at 6-9 but a rangy 210 pounds. Still, averaging 10.3 points and 6.3 rebounds as a sophomore while shooting 56.6 percent from the floor sets the stage for a bigger leap as a junior. If Johnson can become a near double-double guy while improving on the 43 blocks he had in 2013-14, he'll probably be pushing into the lottery.

Dakari Johnson, Kentucky

The Wildcats' returning starter at center will have to share space with three other players – Cauley-Stein, Towns and Lyles – who could be first-round caliber prospects. And like Cauley-Stein, Johnson isn't defined by his 5.3 points and 3.9 rebounds in 14.1 minutes per night. A 7-foot, 265-pound frame will do that, as will the fact that he still will be just 19 years old when the NBA draft rolls around next June. That potential should be too much for a team to ignore.

The Badgers should be a national title contender, and Kaminsky again should be a key reason why. He broke out as a junior to lead Wisconsin with 13.9 points and 6.3 rebounds per game, but it's the 7-footer's ability to shoot from outside -- he made 37 percent from three-point range last season -- that likely would get NBA teams salivating. Surely, the pros would like to see even more bulk on the 234-pound Kaminsky, but his ability to stretch the floor as a pick-and-pop big man will make him an enticing prospect.

The soft-spoken LeVert announced his presence as a sophomore by averaging 12.9 points, 4.3 rebounds and 2.9 assists. He'll need to recover adequately from offseason foot surgery (he's expected to be fine by the start of the season) and add muscle to his 6-6 frame, but his size, long arms and ability to handle the ball should make him a prized commodity. Another small detail working in his favor: Though he is entering his junior season, LeVert will only be 20 at draft time next summer.

Martin is another player long on potential and, well, length, at 6-9 and 241 pounds. He averaged 10.3 points and 4.6 rebounds and shot 47.1 percent from the floor in a promising freshman season, though he posted just one double-double. The numbers alone wouldn't suggest top-tier draft slotting in 2015, but Draft Express has Martin pegged as a top-20 pick at the moment. It was likely a good decision to him to return to LSU for one more year at least, and if Martin takes advantage of that, he could inch up the boards.

There wasn't much scuttle about Portis potentially making the leap after his freshman season with the Razorbacks. But he's 6-10, 242 pounds and averaged 12.3 points and 6.8 rebounds per game while shooting 50.9 percent from the field and 73.7 percent from the line. If those numbers continue to improve, he'll enter into the thick of the draft discussion, especially if he pushes Arkansas to its first NCAA tournament since 2008.

It will be interesting to see if the arrival of five-star swingman Kelly Oubre mitigates the offensive responsibility Selden seems primed to assume as a sophomore. But he has an NBA-ready frame (6-foot-5, 230 pounds) and a willingness to defend in his favor. If Selden can improve on 43.7 percent shooting overall and 32.8 percent efficiency from beyond the arc, as well as the modest 9.7 points per game he averaged in 2013-14, he could leap up draft boards.

The "next Kevin Garnett" didn't make it to campus until the second semester of 2013-14 and didn't make it onto the floor until February, after which he averaged just 4.8 minutes per game. But Walker is 6-10 and said he had already added 15-20 pounds by the time the Final Four rolled around. He will benefit next season from an uninterrupted year of basketball and off-court workouts as well as an enhanced role for the Gators. Even if the numbers don't dazzle in his sophomore year, his frame and potential will be NBA catnip.

The guess is that Wright will get nicked for being “aged,” as he will be 23 years old by draft night next year. But he led a balanced Utah team with 15.5 points, 6.8 rebounds, 5.3 assists and 2.5 steals per game while shooting 56.1 percent from the floor. That sort of across-the-statsheet production has helped make Shabazz Napier a first-round prospect this year. Wright, meanwhile, has a sturdy 6-5 frame to complement the statistical output. If he performs well in a rugged Pac-12 next year, Wright will catch the eyes of NBA scouts and executives.